Hi,all:bigwave:

Somebody know the PnT chart? It oftenly acted on attribute datas.
I would like to know how to use the PnT chart.
Your any feedback will be appreciated!
Thanks!

chenkozou,

I have never heard of that sort of chart. I have heard of P charts and NP charts that are used with attribute data. A quick search here and with Google doesn't return anything, either.

Where did you see this sort of chart? Can you describe the features or the use of the chart? That might help people know what you are looking for.

If this is a customer request, it is often a good idea to just check with them to see what they want.


Tim F

Dear Tim,

Thanks your advise!:applause:

I find PnT charts in some training materials. PnT charts can be replaced to P charts and nP charts.
The control limits of PnT charts were simplified to (3,0,-3) based on 3 sigma principle.
I know PnT charts were used in some Chinese companies, now I want to know if the other country's company are also used the PnT charts. I also want to know how did you apply PnT charts.

Thanks!

I also never hear about PnT charts:(

But as you describe it looks sort of a Z chart for attributes {the values are transformed to Z values by (Value - Mean)/stdev}, it could be T for "Target" but I just a supposition { so (Value - Target)/stdev_historical}.

About the use of such sort of chart, I may suppose that all patterns rules that could be meaningfull for you ( I never recommend all of the GE rules because autocorrelation could give too many false alarms).